10. Head/Taillights Do Not Go Out-Lights ON, Key OFF, Door Open
CIRCUIT OPERATION
When the driver's door is opened while the lighting switch is on and the ignition switch is "OFF" the ETACS-ECU sends a light off signal to the FRONT-ECU, causing the headlights and taillights to light on.
TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU monitors the front door switch, ignition switch, and lighting switch. If these switches satisfy certain conditions, the headlight auto off function works.
TROUBLESHOOTING HINTS
- Malfunction of the column switch
- Malfunction of the front door switch (LH)
- Malfunction of the ETACS-ECU
- Malfunction of the ignition switch
- Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
MB991223: Harness set
MB991502: Scan Tool (MUT-II)
MB991529: Diagnostic Trouble Code Check Harness
CAUTION: To prevent damage to scan tool MB991502, make sure that the ignition switch is "OFF" before connecting or disconnecting the scan tool.
STEP 1. Check the input signal from the ignition switch, using either scan tool or a voltmeter.
- Using scan tool MB991502
1. Connect Scan Tool MB991502 to the data link connector.
2. Check that the tone alarm of the scan tool sounds when the ignition key is moved from the "LOCK" position to the "ON" position.
If the tone alarm of the scan tool does not sound, input signal from the ignition switch is not normal.
Go to Step 2.
If the tone alarm of the scan tool sounds when the ignition switch is normal, go to Step 6.
- Using a voltmeter
1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. If a voltmeter indicator deflects once when the ignition key is moved from the "LOCK" position to the "ON" position. The ETACS-ECU input signal for that ignition switch is normal.
If the input signal of the ignition switch is not normal, go to Step 2.
If the input signal of the ignition switch is normal, go to Step 6.
STEP 2. Check the ETACS-ECU power supply.
1. Remove the instrument panel side cover.
2. Disconnect ETACS-ECU connector C-86.
3. Turn the ignition switch "ON."
4. Measure voltage between ETACS-ECU connector C-86 terminal number 11 and ground.
- Voltage should be approximately 12 volts (battery positive voltage).
If approximately 12 volts, repair the ETACS-ECU.
Check that the malfunction is eliminated.
If not approximately 12 volts, go to Step 3.
STEP 3. Check the ignition switch for continuity.
1. Remove the column covers, lower and upper.
2. Disconnect the wiring connector from the ignition switch.
3. Operate the ignition switch, and check for continuity between the terminal.
If continuity, go to Step 4.
If no continuity, repair the wire or switch.
Check that the malfunction is eliminated.
STEP 4. Check harness connector C-86 and the ignition switch for damage.
If harness connector C-86 is damaged, repair or replace it. Refer to Harness Connector Inspection.
If harness connector C-86 is in good condition, go to Step 5.
STEP 5. Check the harness wires between ETACS-ECU C-86 and the ignition switch.
If any harness wires between ETACS-ECU C-86 and the
ignition switch are damaged, repair them. Refer to Harness Connector Inspection.
If harness wires are in good condition, repair the ETACS-ECU and check that the malfunction is eliminated.
CAUTION: To prevent damage to scan tool MB991502, make sure that the ignition switch is "OFF" before connecting or disconnecting the scan tool.
STEP 6. Check the input signal from the driver's door switch, using either the scan tool or a voltmeter.
- Using scan tool MB991502
1. Connect Scan Tool MB991502 to the data link connector.
2. Check that the tone alarm of the scan tool sounds when the driver's door is opened.
If the tone alarm of the scan tool does not sound, the input signal from the driver's door switch is not normal. Go to Step 7.
If the tone alarm of the scan tool sounds when the driver's door switch is normal, repair the ETACS-ECU. Check that the malfunction is eliminated.
- Using a voltmeter
1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. If a voltmeter indicator deflects once when the driver's door is opened, the ETACS-ECU input signal for that driver's door switch is normal.
If the input signal of the driver's door switch is not normal, go to Step 7.
If the input signal of the driver's door switch is normal, repair the ETACS-ECU and check that the malfunction is eliminated.
STEP 7. Check driver's door switch continuity.
1. Remove the driver's door switch.
2. Check for continuity at the driver's door switch.
If continuity, go to Step 8.
If no continuity, repair the wire or switch.
Check that the malfunction is eliminated.
STEP 8. Check driver's door switch connector D-21 for damage.
If harness connector D-21 is damaged, repair or replace it.
Refer to Harness Connector Inspection. If harness connector D-21 is in good condition, go to Step 9.
STEP 9. Check the harness wires between driver's door switch connector D-21 and ETACS-ECU connector C-86.
If any harness wires between driver's door switch D-21 and ETACS-ECU C-86 are damaged, repair them.
If the harness wires are in good condition, go to Step 10.
NOTE: After inspecting the intermediate connector C-67 and junction block connector C-67, inspect the wire. If intermediate connector C-67 and junction block connector C-87 are damaged, repair or replace them. Refer to Harness Connector Inspection.
STEP 10. Check the harness wires between driver's door switch connector D-21 and body ground.
If any harness wires between driver's door switch connector D-21 and body ground are damaged, repair them and check that the malfunction is eliminated.
Then go to Step 11.
STEP 11. Check symptoms.
Confirm that the headlight auto oft system operates normally.